[dsraven]

possibly use rubber pads under the vibrating stuff, like the air compressor. I have an 80 gallon upright unit and bolted it down to a laminated piece of plywood to achieve 1 1/2" thick. there is rubber between the compressor legs and the plywood so that helps. the air intake also goes into the attic space so it is way less loud when it runs. it kinda sounds like a truck running somewhere when you are outside the shop. the neighjbours have never said anything about it so I think it may be just me who pays attention to the compressor noise. if your attic is shared you maybe don't wanna do that trick.